This page outlines the purpose of this resource and the general procedures for its use.

Goals and Mission

arXiv is an openly accessible, moderated repository for scholarly articles in specific
scientific disciplines. Material submitted to arXiv is expected to be of interest,
relevance, and value to those disciplines. arXiv reserves the right to reject or
reclassify any submission. Submissions are reviewed by expert moderators to verify
that they are topical and refereeable scientific contributions that follow accepted
standards of scholarly communication (as exemplified by conventional journal articles).

As an electronic archive, arXiv makes a commitment to provide persistent access to all
announced submissions. arXiv is thus maintained with a focus on the perpetual
availability of submissions. This is accomplished in part by controlling the types of
files that can be uploaded to arXiv, as well as restricting changes that can be made
after submissions are announced. In order to preserve the scholarly record, submissions
are not removed from arXiv after they have been announced.

arXiv is proud to be able to offer such a large collection of scholarly work in a single
location, without any fees and with support for users around the world. arXiv supplements
the traditional publication system by providing immediate dissemination and open access to
scholarly articles (which often later appear in conventional journals). It is important to
note, however, that arXiv is not a repository for otherwise unpublishable material, nor is
it a refereed publication venue. The moderation process is essential to ensuring that
submissions are of value to the arXiv communities, but there is also a limit to the
ability of administrators and moderators to provide feedback on submissions that are
determined to be inappropriate for arXiv.

As a user, your primary interactions with arXiv will likely be to browse and view articles,
and perhaps also to submit articles. Submitting articles requires registration as a user,
whereas browsing can be done without registration, on either the main
arXiv.org site or on any of arXiv's
mirror sites around the world.

Browsing arXiv

All arXiv submissions are freely available, often in multiple formats. Each submission has
an "abstract" page where summary metadata for the submission are displayed, along with the
available download formats and any additional services that apply to that particular submission.
Examples of extra services include trackbacks, INSPIRE reference data,
and chronological or subject-specific arXiv browsing via "previous" and "next"
links. Please note that some of the services mentioned are third-party services that may not
be available for every submission and that are maintained by different administrative staff.
Check carefully any of the offered pages for additional information and separate help
documentation.

It may be tempting attempt to download a local copy of arXiv or to build a dataset of
articles for research. The system, however, is not designed to withstand automated downloads.
Accesses are thus monitored and the system will block sites
attempting large downloads or making rapid-fire requests in order to protect access for other
users. Access blocks can also be triggered by PDF plug-ins sending
accelerated requests to our server. To avoid triggering a block, make sure you are not
allowing your browser to open the PDF files with a plug-in, and do not download a large
corpus of articles very quickly. You can also use one of our many mirror sites to download
papers instead of increasing the load on the main server.

Submitting to arXiv

arXiv accepts submissions of scholarly articles in a variety of formats from registered,
endorsed users. The submission process can begin any time after the user has successfully
registered and involves several stages:

arXiv submissions are meant to be available in perpetuity. Thus, arXiv has high technical
standards for the files that are submitted. The submission process begins with the preparation
of valid metadata for the paper and continues through a verification process whereby the files
uploaded are checked for certain problems. Valid upload formats for the primary text file
include (La)TeX, PostScript, PDF, and HTML. There are specific restrictions
for each of the primary file types and only certain other supplementary file types are acceptable; please
consult the submission instructions for additional information. If there are problems with
the metadata, error messages on the screen should help you make corrections. If there are
problems with the files, an error report will be generated and the files will be assigned a
rejection id. In this case you should read the log and attempt to correct the problem, or
failing that send the rejection id to the arXiv administrators for assistance.

User Endorsement

If you are a new user or are submitting to a new archive, you may be required to find
endorsement
before your submission will be processed. Users with recognized academic affiliations may be
exempt from the endorsement process, while other users should contact
eligible arXiv endorsers
to verify that they are active members of the scientific community. This process helps restrict
arXiv submissions to relevant and legitimate research contributions without adding to the
administrative cost of arXiv, and thus it is an essential contribution to both the legitimacy and
the sustainability of arXiv as a free resource.

Pending Submissions

arXiv submissions are not "announced" (made available to the public) immediately after they are
uploaded. Instead, submissions receive a pending status until the next "freeze time". (The freeze
time is the daily submission deadline. This is always 16:00 US eastern time (EST/EDT) on working
business days, and the time until the next deadline can be found on our local
time page.) If the
files are accepted, you will be assigned a tentative arXiv id, and the system will send two
notification emails to your registered email address. One email will contain a copy of the metadata
and a link to the submission. The other email will contain the tentative arXiv identifier and the
paper password, which can be sent to co-authors so that they can also claim ownership of the paper.

Submission Replacements

If, after initial submission, you need to make corrections, do *not* use the back button on the
browser to return to the submission form since this will create a duplicate submission. Instead,
you can correct errors or upload revisions for your submissions by making a
replacement.
Replacements made before the "freeze" deadline for the day will overwrite the original submission.
Only the last files uploaded before the freeze time will be made publicly available. Replacements
must always compile separately, which means that all necessary files must be included, even if they
have not changed from the previous version. While the submission is pending, however, the replacement
form will also offer the option of editing only the metadata. Simply select the "metadata only" box
at the bottom of the form. If you encounter technical problems with your submission that you cannot
correct through replacement, please make sure you have explored our help pages before contact arXiv
administrators for assistance.

Submission Versions

After the freeze time, any replacement will create a new version. The new version will be available
for viewing on the same page as any older versions; the newest version is always the default version
of an article displayed. arXiv maintains a separate record for each version submitted, and all
information will remain available as it was announced. Just as we do not remove submissions after
they have been announced, we do not remove versions after they have been announced. If you have
found a critical error in your submission, you can submit a withdrawal notice.
The withdrawal does not remove any previous version of the submission, but it allows the
author to explain any problems with the submission.

Submission Availability

Submissions are typically made publicly available and announced within a single business day,
if they are not removed for technical or moderation concerns. That is, a paper that is
submitted during before the freeze on a Tuesday will be made publicly available Tuesday evening
at 20:00 US eastern time and announced via email a few hours later. Submissions made before
the freeze time on Friday, however, are not announced until Sunday evening, and the submissions
from the weekend are all pending until the Monday freeze. For more information, see the
availability schedule.

Submission Moderation

All arXiv submissions are subject to moderation and may be removed (while pending) or reclassified
(at any time). Please see our moderation help page for a full description of
the moderation process and the reasons a submission might be removed or reclassified.

Other Submission Actions

Finally, some changes can be made to a submission without submitting a full replacement. Submissions
can be cross-listed to another archive or subject classification without submitting
a replacement. Cross-listing adds the submission to the mailings for the new category and makes it available
in searches restricted to the other category. The journal reference, report number, and DOI metadata
fields can also be modified separately by using a special form. Any other changes,
including changes to the Comments field, must be made in conjunction with a full replacement of the
submission, including all necessary files.

Contacting arXiv administrators

arXiv administrators respond to technical and moderation queries during standard business hours on weekdays.
All administrators are located in New York, USA, and you should take the local time
into account when you plan your submissions and attempt to contact the administrators. If you have any
problems with arXiv, we encourage you to explore the help documentation and
Frequently Asked Questions thoroughly before contacting the administrators. This
will often result in a much faster answer to your question. If you are still unable to resolve your issue,
do *not* attempt to trick the system or circumvent arXiv controls - for example, by removing required figures
from your submission, or by submitting a TeX document embedded within an HTML file. You should send a
description of the problem to the administrators, after reading the contact instructions
for information on how to address queries and what information is required to resolve problems. We will make
every effort to respond to your question in a thorough and timely manner.